A correlation of the structural alterations in the connective tissue components of gingiva with the histological and clinical manifestation of periodontal disease will provide more information on the molecular basis and etiology of the disease. Although morphological changes in the periodontium are striking features of periodontal disease, data on the molecular alterations occurring during the pathogenesis of the disease are still lacking. Detailed structural studies at the molecular level of the protein components of the gingival matrix from healthy and diseased tissues are proposed. Insoluble collagen will be solubilized by treatment with CNBr or by limited enzyme digestion. Physicochemical methods will be used for characterization of the gingival matrix proteins. The state of these proteins in human gingiva may serve as parameters to assess the progress of a pathologic condition.